In last weekend's Guardian, Malcolm Gladwell, who is over here on a lecture tour to promote his new book, What the Dog Saw, remarked that he found himself "drawn to artists with long careers – people who are consistently creative". In support of this interesting observation, Gladwell cited the example of Paul Simon. "Song by song," he said, "he isn't my favourite artist. But I can't get over the fact that he made great music in the 60s, the 70s, the 80s and the 90s. That's extraordinary."

There are surprisingly few Paul Simons in the world of books. Songs can be – have been – written on train rides or cigarette breaks. They mostly take four minutes to perform, on average. A novel is an infinitely more demanding proposition; the musical equivalent would be an album.

On Grub Street, as in Tin Pan Alley, the artist's professional trajectory is inevitably uncertain. In literature it makes no sense to talk of "a career" in the sense of a life that can be managed by the exercise of prudent thought. Writers who flourish at the peak of their powers for longer than a decade, or even two, are rare birds.

There are exceptions. Writers who work in a genre, John le Carré for example, or PD James, are more likely to sustain a run of quality and a sequence of winners. In this connection, I note with interest that Zadie Smith, after a brilliant beginning from 2000 (White Teeth) to 2005 (On Beauty), is currently recharging her batteries, working on essays, some of which appeared in 2009 under the title Changing My Mind. Enough said.

Anyway, do we really want consistency in an artist ? What does this pressure to please the market have to do with art ? Originality involves risk, and risk implies the possibility of failure. That's how greatness is born. Melville was acclaimed for Typee and Omoo. Then he immersed himself in Moby-Dick and eventually died penniless and obscure.

Original work is, by definition, exceptional. Often, it seems to come out of nowhere in a explosive flurry of excitement. Anglo-American and European literature is notable for its sprinters as well as its long-distance runners. There are so many brilliant one-offs, especially at the more popular end of the business: Margaret Mitchell's Gone With The Wind, or Harper Lee's To Kill A Mockingbird, for example. Rosamond Lehmann had a long career, but most readers know her for The Weather in the Streets. Many lesser writers would happily settle to be remembered for just one title. An oeuvre may be too much to ask.

Sometimes, there are writers who seem born to produce just one book. Ralph Ellison published Invisible Man in 1952 and spent the rest of his life trying to follow it. Malcolm Lowry's Under the Volcano was the fruit of a life-and-death struggle. Jack Kerouac's On the Road towers above all his other books, and he died an alcoholic aged 47. Guiseppe di Lampedusa's The Leopard was not fully recognised until after his death.

Either way, in songs or novels, sustaining a lifetime's work as a writer is exceedingly difficult. Most literary careers begin, and possibly end, before the age of 40. Some fly too close to the sun, and fall to earth; others give up, exhausted and demoralised.

Take the influential triumvirate of Orwell, Waugh and Greene, who were born within a few months of each other in 1903-04. Waugh went mad. Orwell died of TB, and even that great survivor Greene's late work shows a falling off.

More recently, Iris Murdoch enjoyed perhaps three decades of critical appreciation and wide popular sales, but is now almost forgotten. William Golding, who died in 1993, is remembered, in the words attached to a recent biography, as "the man who wrote Lord of the Flies".

A forthcoming TV adaptation of Money, a modern classic from the 1980s, comes on the heels of Martin Amis's The Pregnant Widow. This might be a reminder that you can still find a few grizzled veterans ready to saddle up for one more charge against the murderous cannon fire of indifference and critical disdain. But there's not quite the elan of more youthful engagements. Perhaps Mr Amis would rather write a hit song.

If you've been convoked, you've got a poetry vote

As the nominations for the Oxford professor of poetry close, the frontrunner and bookies' favourite is the reclusive Geoffrey Hill. Meanwhile, the organisers point out that voting is not "only open to Oxford MAs", as reported here on 9 May. Apparently all members of convocation (those who have received a degree from Oxford and completed a degree ceremony) as well as members of congregation (the governing body of academics and senior administrators) can vote. One poet who will sadly not be in contention along with Sean Haldane, Stephen Moss or Steve Larkin, the popular performance poet, is our own Victor Keegan, who has published his third collection as an iPhone app. Although the Oxford post will be contested online (giving an advantage to Larkin), it's hard to see Hill following the digital trend, sadly.

At last, Alastair can tell the unvarnished truth

One positive outcome from the departure of Gordon Brown and New Labour from Downing Street must be the unmuzzling of Alastair Campbell, who is now free, presumably, to spill the beans over 13 years at the centre of power. So keen, in fact, is Random House to have the great spin doctor on board that Hutchinson will shortly publish the "unexpurgated" version of its already published The Blair Years. It remains to be seen how much appetite the reading public will have for the inside story of the TB-GB rows now that there's a new set of potential adversaries, Messrs Cameron and Clegg, inside No 10.